Determination of oxidation states of uranium and plutonium in cooling solution of spent fuel element assemblies from NPP A-1

The knowledge of oxidation states of uranium and plutonium is necessary from the point of view of the proposed vitrification technology for the final liquidation of the cooling solution as a high radioactive waste containing alpha activity. The valence states of uranium and plutonium have a major influence on the subsequent leaching rate of these elements from vitrification matrices. Using the various chemical behaviours of these elements, in accordance with their valence states, we made an attempt to establish their oxidation state in the original solution.